The major division of health care appeared in many societies between private curative and public preventive health care. This influenced all types of health services, hospitals and primary health care units, as well as education of professionals and research. The opponents of integration have been pointing out negative experiences with integration because preventive services often have been ""eaten up"" by curative services. A special service is used in vertical programs as a vehicle to provide necessary procedures and activities to cover groups ""at risk"". There are several characteristics of vertical programs which determine their role in primary health care, which are analyzed in this module.